Rollup merge of #100524 - ohno418:impl-debug-for-some-rustbuild-structs, r=Mark-Simulacrum

Impl `Debug` for some structs of rustbuild

A small patch to impl `Debug` for some structs of rustbuild to make debugging easier.

(I was trying to impl `Debug` for the `Config` struct, but found to have a bit more things to do. So gave up for now.)

src/bootstrap/flags.rs

@@ -80,6 +80,7 @@ pub struct Flags {
     pub llvm_profile_generate: bool,
 }
 
+#[derive(Debug)]
 #[cfg_attr(test, derive(Clone))]
 pub enum Subcommand {
     Build {

src/bootstrap/setup.rs

@@ -11,7 +11,7 @@ use std::{
     io::{self, Write},
 };
 
-#[derive(Clone, Copy, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub enum Profile {
     Compiler,
     Codegen,